Immunoelectron study of pancreatic carcinomas using antibodies to gastrointestinal hormones

The aim of this study was to investigate the ultrastructural appearance of pancreatic adenocarcinoma combined with glucagon and gastrin/cholecystokinin (CCK) expression. The authors investigated the ultrastructure and the immunocytochemistry of 12 human pancreatic cancer specimens and used 3 chronic pancreatitis samples and 6 adjacent histological normal pancreatic tissues (away from the tumor) as controls. The ultrastructural study revealed that chronic pancreatitis tissues were characterized by alterations of the secretory cells. The enzymic and secretory changes were confirmed by electron immunogold results. Glucagon appeared to be located not only in islet alpha cells but also in intermediate alpha acinar cells. The changes were more significant in adenocarcinoma cases. Abnormality in the immunoreaction of the peptides was indicated not only in the tumor area but also in the islets near the cancer. Cells immunoreactive with antibodies were found in all 12 adenocarcinoma cases. Abnormal co-location of both hormones in the same type of endocrine cell was also found. Moderately to poorly differentiated adenocarcinomas were poorly granulated compared with differentiated tumors. Increased and ectopic gastrin/CCK expression was correlated with pancreatic adenocarcinomas exhibiting poor histological grade and neoplastic endocrine cells, providing a potential marker for pancreatic adenocarcinomas with aggressive behavior.